1. Field of the Invention
The present invention relates to an optical disc having a memorizing means, into and from which data can be recorded and reproduced afterwards, separately from an area in which disc information is recorded.
2. Description of Related Art
In recent years, various systems are manufactured, wherein a recording disc is used as a recording medium, which can be produced easily through mass production and is high in reliability thereof. Representative examples of them are, for example, so-called a compact disc, being an optical disc for use in music (hereinafter, abbreviated by xe2x80x9cCDxe2x80x9d), a digital versatile disc, being an optical disc for use in video, such as movies (hereinafter, abbreviated by xe2x80x9cDVDxe2x80x9d), and CD-RM or DVD-ROM, being applied to for use of memorizing various data, such as application software and game software for use in computers, etc.
The optical discs, such as the CD, CD-ROM, DVD and DVD-ROM, etc., being made of plastic material, can be produced cheaply and in large quantity thereof by using a mold, as the discs in which data are already recorded. On the other hand, since they are for use in reproduction only (i.e., read only discs), data cannot be recorded afterward thereon. Therefore, it is impossible to process the data on the disc, so as to record the result thereof on the disc for reservation, nor to record the count number in using the disc, in a part thereof for reservation. Accordingly, when trying to apply the discs to an information management system, such as for reservation of the result of playing the game, etc., limitation or restriction for use of the application software and/or limitation or restriction for reproduction of the information, such as music and/or movies, they are inconvenient nor not necessarily convenient. Of course, there exists a disc on which such the data can be recorded, however, it cannot be produced cheaply in large quantity thereof in such the manner as mentioned above, but rather it comes to be expensive since it necessitates complex processes for manufacturing thereof. Also, when recording data, the data must be recorded onto each disc. Further, for recording, it is necessary to provide an optical head which has an output being higher comparing to that of and apparatus for reproducing only, therefore the price of a recording/reproducing apparatus comes to be expensive.
As, as a method for managing main information on a medium being by means of an other medium separated from that for the main information, there is known a system, in which a semiconductor memory is installed on a magnetic tape cartridge, wherein the management of the information on the magnetic tape is conducted by the semiconductor memory. However, in this case, the semiconductor memory is positioned in the cartridge main body, therefore the access to the semiconductor memory is conducted by contacting to it, directly. Accordingly, though it is possible to apply the method mentioned above into the medium of the disc type, so that such the semiconductor memory is installed on the disc, for example, however in that case, since the semiconductor memory is also rotated by itself with the disc, it has a problem that there is difficulty in transmission of the information thereof.
According to the present invention, it is an object to provide a recording disc for the exclusive use in reproduction (i.e., read-only disc), being made of plastic material, like such as the CD, CD-ROM, DVD, DVD-ROM, etc., which can be manufactured cheaply and can be recorded with a large amount of data thereon, wherein further management information can be recorded and reproduced afterward, with ease and certainty, for applying it to an information management system for the recorded information recorded on the disc, such as the games, the application software, the music and movies, etc., on which no additional information can be recorded afterward, and which can reserve the result of playing the game or can impose restrictions on using the application software or on the number of reproductions, for example.
Also, in such the case, there is caused a problem that vibration becomes large due to decentration or eccentricity in the center of gravity of the disc, when an other separated thing(s) (such as the semiconductor memory) is formed or provided on or in the disc. In particular, under the condition where high rotation velocity is required for the CD-ROM in the recent years, the influence brought by the eccentricity in the center of gravity is large. Further, for the DVD-ROM, there is established a regulation or standard in which the acceptable amount for the eccentricity in the center of gravity is determined, therefore it must be in accordance therewith.
Then, an object according to the present invention is to provide a recording disc, on which is provided a means being recordable afterwards, and which can reduce the eccentricity in the center of gravity for suppressing unnecessary vibration of an apparatus when rotating at high revolution or rotation velocity.
For dissolving the problems mentioned above, according to the present invention, there is provided a recording disc having a reproducible data recording area, comprising:
an input means for electromagnetically inputting data;
a data memory means for memorizing the data which is inputted through said input means;
an output means for electromagnetically outputting the data which is memorized in said memory means; and
a counter balance being provided at a position in an opposite side to a position where said memory means is positioned, on a basis of a rotation center of said disc, within the disc.
And, further, according to the present invention, for example, in the recording disc mentioned above, wherein the counter balance has a mass being nearly equal to that of the data memory means, and is positioned at a position being nearly centrosymmetric to the data memory means, on a basis of a rotation center of said disc.
Alternatively, according to the present invention, in the recording disc mentioned above, wherein said counter balance is provided with a portion in which the information can be written and/or a portion on which a label can be attached.
Alternatively, according to the present invention, in the recording disc mentioned above, wherein the input means and/or the output means are positioned so that the data memory means and the eccentricity in the center of gravity are in balance.
Alternatively, according to the present invention, in the recording disc mentioned above, wherein a plurality of data memory means are provided and are positioned, so that the eccentricity in the center of gravity due to each of the memory means is reduced.
Alternatively, according to the present invention, in the recording disc, in which are provided the plurality of data memory means, the output means for electromagnetically outputting the data recorded in said memory means, and the counter balance within the same disc, wherein they are positioned so that the eccentricity in the center of gravity due to the each means is reduced.
Further, according to the present invention, in the recording disc mentioned above, wherein the eccentricity in center of gravity of said disc is equal or less than 1.0 gcm.
And, further, according to the present invention, in the recording disc mentioned above, there are further provided an electric power input means for electromagnetically inputting electric power to said memory means, and/or a battery means being able to accumulate electric power which is supplied from an outside. Or, there is further provided a solar battery for supplying electric power to said memory means.